JPH10128020A - Filter and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter which excels in absorptivity and gas permeability and can remove fine dust by mixing an absorbent with a granular hot melt based binder in advance and scattering the mixture on a nonwoven fabric base material to fuse the adsorbent on the fiber of the nonwoven fabric base material and also fuse the upstream side, downstream side sheets and the nonwoven fabric base material by the binder. SOLUTION: A downstream side sheet 4 is fed from a first roller 11 with the sticking surface of a fungicide facing downward, and a nonwoven fabric base material 2 is mounted on the downstream side sheet 4 from a second roller 12. On the other hand, a granular adsorbent 5 and a hot melt binder in a hopper 13 arranged downstream side of the second roller 12 are scattered on the nonwoven fabric base material 2. Nest, after and upstream side sheet 3 is mounted on the surface of the upstream side of the nonwoven fabric base material 2 from third roller 14, the upstream side and the downstream side sheets 3, 4 are pressurized and heated in the width direction by a heating press 15 to melt the hot melt binder 6 in the nonwoven fabric base material 2 and fuse the absorbent 5 on the fiber of the nonwoven fabric base material 2. The upstream side, the downstream side sheets 3, 4 are also fused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a filter,
In particular, the present invention relates to a filter capable of adsorbing odors and harmful gases.

[0002]

2. Description of the Related Art In recent years, for example, air-conditioning-related filters for purifying general homes, buildings, and automobile interiors, in addition to dust-collecting performance, have the ability to adsorb adsorbed substances such as odors and harmful gases. Is also needed.

[0003] As a filter having such adsorption performance, there is a filter in which an adsorbent for adsorbing an object to be adsorbed is adhered to a net. However, in such a filter, since the base material to which the adsorbent is adhered is a net, only a small amount of the adsorbent can be adhered, and the adsorption performance is poor. for that reason,
When trying to adhere many adsorbents, the adsorbent tends to fall off.If the amount of the binder is increased to prevent this dropout, the adsorbent's adsorption performance is reduced by the binder and the filter becomes rigid. There is a problem that it is easily damaged.

Therefore, a non-woven fabric is used instead of a net,
For example, (1) a nonwoven fabric is immersed in a solution in which a particulate adsorbent and an emulsion-type binder are mixed and then dried to fix the adsorbent to the nonwoven fabric, or (2) an emulsion-type binder is applied to the surface of the nonwoven fabric. Is applied to fix the particulate adsorbent.

[0005]

However, even in filters using these nonwoven fabrics, if the density of the nonwoven fabric is small (coarse), the same problem as the above-mentioned net occurs. If the density is large, the pressure loss becomes large. When the adsorbent is fixed to the nonwoven fabric, there is a problem that the pressure loss is further increased.

In the former filter (1),
There is a problem in that the adhesive covers the adsorbent and hinders the original adsorption performance. On the other hand, in the latter filter (2), desorption of the particulate adsorbent is apt to occur, and particularly, it is difficult to fix the adsorbent uniformly in the thickness direction. Then, there is a problem that the pressure loss increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to provide a filter which is excellent in adsorption and ventilation performance, does not fall off an adsorbent, has excellent strength, and can remove small dust. It is an object.

[0008]

Accordingly, the invention of claim 1 is to provide a method for manufacturing a nonwoven fabric which can disperse a granular adsorbent in a thickness direction and hold the adsorbent inside the nonwoven fabric on the upstream and downstream surfaces of the substrate. An upstream sheet and a downstream sheet having a void smaller than the agent are disposed, and a filter in which a sheet of a nonwoven fabric having a charge property is joined to the downstream surface of the downstream sheet, wherein the adsorbent is It is mixed with a granular hot-melt binder and dispersed on the non-woven fabric substrate, and the binder fuses the adsorbent to the fibers of the non-woven fabric substrate and forms a mixture with the upstream and downstream sheets. It is characterized by fusing with a nonwoven fabric substrate.

[0009] The method for producing a filter according to the present invention is characterized in that the adsorbent is dispersed in the thickness direction on a downstream sheet having voids smaller than the granular adsorbent and can be held inside. The material is placed, the adsorbent and the granular hot melt binder are mixed and sprayed from above the nonwoven fabric substrate, and the upstream sheet is placed on the nonwoven fabric substrate,
Next, the hot melt binder is melted by heating,
The above-mentioned adsorbent is fused to the fibers of the non-woven fabric substrate, and the above-mentioned upstream and downstream sheets are fused to the non-woven fabric substrate. It is characterized by joining.

[0010] In the present specification, a non-woven fabric is defined as a sheet in which one fiber and one fiber are accumulated, and the fibers are chemically bonded to each other with a binder such as a polymer resin (latex bonding method). Alternatively, it refers to a fabric formed by pressing fibers together by heat (thermal bond method) or mechanically entangled fibers (needle punch method, water entanglement method).

As a method of accumulating fibers in a sheet shape,
In the same way as spunbonding, meltblowing, flash spinning, or spinning the fiber directly from the original raw material of the fiber, or carding the fiber by mechanically arranging it with a card similar to spinning, or straining the paper A wet method for straining, and the like can be given.

[0012] Examples of the fibers include polychloral fibers, vinylidene fibers, polyvinyl chloride fibers, polyester fibers, polyamide fibers, acrylic fibers, polyvinyl alcohol fibers, polypropylene fibers, polyethylene fibers, and composite fibers composed of a plurality of resin components. Synthetic fibers such as, or a mixture of aromatic fibers, antibacterial agents and fungicides mixed with these synthetic fibers to provide aromatic, antibacterial and antifungal properties, and regenerated fibers such as rayon and viscose. ,
Semi-synthetic fibers such as acetate, and inorganic fibers such as carbon fiber and glass fiber can be used. Among these, polychloral fiber, vinylidene fiber, and polyvinyl chloride fiber have excellent flame retardancy, and polyester fiber has chemical resistance,
Since it has excellent heat resistance, it can be suitably used as the nonwoven fabric according to the present invention. The average fiber diameter of the fibers is preferably 20 to 35 μm in consideration of pressure loss and substrate strength.

The upstream and downstream sheets used in the present invention have voids smaller than the adsorbent in order to minimize spillage of the particulate adsorbent, and have a thickness smaller from the viewpoint of reducing pressure loss. It is preferably thin, specifically, the basis weight is 10 to 100 g / m ² and the thickness is 0.1 to 1.0 m.
m is preferable. It should be noted that several nonwoven fabrics having a coarser grain size than the activated carbon may be stacked to make the grain finer. As an example, the nonwoven fabric obtained by the above-mentioned melt blow method or the like can be used as it is for the upstream and downstream sheets.

The same sheet can be used for the upstream sheet and the downstream sheet. However, if the upstream sheet is made coarser than the downstream sheet, the upstream sheet and the downstream sheet can be used from the upstream side to the downstream side. The eyes become denser, and the inflowing dust is less likely to be clogged in the upstream sheet, so that the life of the filter is improved. In addition, small dust can be reliably captured by the downstream sheet, and the filtering performance is improved.

In order to provide the filter with antibacterial and antifungal properties, for example, an antibacterial agent and an antifungal agent are respectively applied to the surfaces of the upstream and downstream sheets in advance at 0.1 to 5 gr / m 2.
^{About 2} can be fixed.

On the other hand, the base material of the nonwoven fabric serving as the intermediate layer is slightly coarser than the size of the particles of the adsorbent so that the particulate adsorbent can be dispersed in the thickness direction and arranged three-dimensionally. A low-density material having a thickness is preferable. For example, the weight is preferably about 20 to 100 g / m ² and the thickness is about 0.5 to 10 mm. Here, if the size of the particulate adsorbent and the size of the mesh of the nonwoven fabric substrate are adjusted so that the dispersed adsorbent becomes denser toward the downstream side, the durability and filtration performance of the filter are further improved. I do.

The above-mentioned particulate adsorbent effectively adsorbs to-be-adsorbed substances such as odors and harmful gases, and includes, for example, iron, manganese, copper, aluminum, magnesium, zinc, nickel, cobalt, platinum, palladium, and the like. Gold, ruthenium,
Simple metals such as rhodium, these metal oxides, these metal chlorides, zeolite, kaolin, sepiolite,
Silica gel, activated carbon and the like may be used alone or in combination. If the average size of the adsorbent is too large, the filter becomes thick and the folding process becomes difficult, and if the average size is too small, the amount of the adsorbent decreases and the adsorption performance decreases. 1.7mm)
The degree is preferred.

If the amount of the particulate adsorbent sprayed on the nonwoven fabric substrate is too small, the adsorption function is reduced, and if it is too large, air permeability may be impaired. / M ² , more preferably 200 to
It is about 350 g / m ² .

As the hot melt binder, hot melt type granules having thermoplasticity are used, and those which do not significantly reduce the deodorizing performance of the adsorbent are preferable. As such a hot-melt binder, for example, polyester-based, polyamide-based, urethane-based, polyolefin-based, ethylene, and vinyl chloride (EVA) -based binders can be used.
Among these, vinyl chloride resins are excellent in flame retardancy, and therefore can be suitably used.

The amount of the hot-melt binder is preferably 10 to 100% by weight based on 100% by weight of the adsorbent. When the amount of the binder is less than 10% by weight, the binder easily falls off in spite of using the binder,
Adhesion between the upstream and downstream sheets and the nonwoven fabric substrate tends to be insufficient. In addition, the manufactured filter may be soft, and folding may be difficult. On the other hand, if the amount of the binder exceeds 100% by weight, the binder covers the adsorbent, which may impair the adsorption performance.

As a method of manufacturing a filter, first, a nonwoven fabric substrate is placed on a downstream sheet, and then a predetermined amount of a particulate adsorbent and a hot melt binder mixed in advance are mixed on the nonwoven fabric substrate. Spray. Next, after the upstream sheet is placed on the nonwoven fabric substrate, the hot melt binder is heated so as to be melted, and the adsorbent is fused to the fibers of the nonwoven fabric substrate. The non-woven fabric substrate is fused.

By the way, in order to further improve the dust collecting performance, the upstream and downstream sheets and the nonwoven fabric substrate itself are provided with:
It is conceivable to use a non-woven fabric sheet having chargeability, but when such a charge sheet is used, the chargeability is weakened when the filter is heated to melt the hot melt binder during the production of the filter. However, the desired performance as a charged sheet cannot be obtained. Therefore, it is conceivable that an electric field is applied to the filter after the above-described heat treatment at the time of manufacturing the filter to impart the chargeability without using such a charged sheet. However, in this case, for example, the nonwoven fabric substrate holding a conductive adsorbent such as activated carbon inside easily discharges, so that a strong electric field cannot be applied. It is difficult to uniformly impart strong chargeability to a filter having a thickness.

Therefore, in the present invention, after the heat treatment is performed as described above, a nonwoven sheet having a chargeability is joined to the downstream surface of the downstream sheet. As a method of this bonding treatment, for example, a molten hot-melt type binder is sprayed on a bonding surface of the downstream sheet or the charged sheet using a spray or the like so as not to apply heat as much as possible. Glue.

The filter thus obtained may be used as a flat plate, but if it is folded, the surface area which can act on the fluid can be increased.
Excellent in adsorption performance and dust collection efficiency.

In the filter thus manufactured, the nonwoven fabric substrate has a laminated structure sandwiched between the upstream and downstream sheets, so that the nonwoven fabric substrate is protected from friction during manufacture and use. At the same time, an appropriate strength is mainly given by the upstream and downstream sheets, and the folding can be easily performed. In addition, since the upstream sheet and the downstream sheet have voids smaller than the granular adsorbent, falling off of the adsorbent during manufacturing and during use is effectively prevented.

Since the dispersed particulate adsorbent is entangled between the fibers inside the nonwoven fabric substrate and is maintained in a three-dimensional arrangement appropriately dispersed in the thickness direction, the air permeability and the adsorption performance are reduced. Are better.

In addition, the adsorbent is fused to the fibers of the nonwoven fabric substrate by the hot melt binder,
Since the downstream sheet and the non-woven fabric base material are fused together, the particulate adsorbent during use is prevented from falling off, and the upstream and downstream sheets and the non-woven fabric base material are separated using a separate binder or the like. It is not necessary to glue, and the manufacturing process is simplified.

Since the non-woven fabric sheet having a charge property is bonded to the downstream surface of the downstream sheet, it is also possible to remove small dust that cannot be normally captured, such as cigarette smoke and exhaust gas. . Note that since the charged sheet is bonded after the heat treatment, the dust removal performance does not decrease due to the influence of the heat treatment.

Since the adsorbent and the particulate binder are mixed in advance, the binder easily adheres around the adsorbent, and the thus adhered binder is melted by heating. It is believed that the adsorbent bonds with the fibers of the nonwoven substrate.
Also, the hot melt binder that has passed through the eyes of the nonwoven fabric substrate and dropped on the downstream sheet bonds the downstream sheet and the nonwoven fabric substrate, while the hot melt binder remaining on the upper surface of the nonwoven fabric substrate Seems to adhere the upstream sheet and the nonwoven fabric substrate.

When there is a possibility that the adhesion between the upstream sheet or the downstream sheet and the nonwoven fabric substrate is weakened only by the sprayed hot-melt binder, the downstream surface of the upstream sheet and the downstream sheet of the upstream sheet may be weakened. A hot-melt particulate binder may be fixed to one or both of the upstream surface of the downstream sheet in advance. In this case, the binder fixed in advance is also melted by heating together with the dispersed binder,
The adhesive strength between the upstream and downstream sheets and the nonwoven fabric substrate increases.

Further, by adding a granular fungicide or a bactericidal agent together with the granular adsorbent or the hot-melt binder before spraying, the filter can be easily provided with a fungicidal and germicidal function. Can also be provided.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 3, but the present invention is not limited to the embodiment described later.

34 g / m 2 obtained by a polyethylene terephthalate (PET) spunbond method on the upstream side sheet
^2, a nonwoven fabric of 30 g / m ² obtained by the PP spunbond method on the downstream side sheet, and a nonwoven fabric substrate of 30 g / m ²
m ² thermal bond nonwoven fabric (PP / PE), activated carbon having an average size of 20 to 40 mesh as a granular adsorbent, and a granular hot melt binder are used.

Further, 1 g / m ² of an antifungal agent previously dispersed in a solvent binder is applied to one surface of the upstream and downstream sheets using a high-speed transfer machine for printing, and then dried and fixed. . Further, the hot-melt binder was fixed to 10 g / m ^{2 on the} other surface of the upstream sheet to which the antifungal agent was not applied by using a laminating machine. Further, the activated carbon was inclined at 25 to 30 degrees as shown in FIG.
The mesh is flowed from the upstream side of the stainless mesh 21 of 0 mesh or 2 m or more to remove fine powder in advance.

FIG. 1 shows an apparatus for manufacturing the filter 1 of this embodiment, and a method of manufacturing the filter 1 will be described with reference to FIG.

First, from the first roller 11 to the downstream sheet 4
Is supplied with the antifungal agent fixing surface down, and the nonwoven fabric substrate 2 supplied at a constant speed from the second roller 12 is placed on the downstream sheet 4. On the other hand, the hopper 13 disposed downstream of the second roller 12 is filled with the granular adsorbent 5 and the hot melt binder 6 by stirring.
From the open lower end of the hopper 13, the granular adsorbent 2
80 g / m ² and the hot melt binder 50 g / m ² are sprayed on the nonwoven fabric substrate 2.

Next, the upstream sheet 3 supplied from the third roller 14 at a constant speed is applied to the upstream surface of the woven fabric substrate 2.
Are placed on the nonwoven fabric substrate 2 while the upstream and downstream sheets 3 and 4 are pressed in the width direction and heated in the heating press machine 15. The hot-melt binder 6 held by the non-woven fabric substrate 2 is melted, the adsorbent 5 is fused to the fibers of the non-woven fabric substrate 2, and the upstream and downstream sheets 3, 4 and the non-woven fabric substrate 2 are fused. Is done. Next, a hot melt binder is sprayed on the downstream surface of the downstream sheet 4 of the filter supplied from the heating press 15, and immediately after that, the charged sheet 7 supplied from the charged sheet roller 16 is attached to the downstream sheet 4. Join to attach. Thereafter, the filter 1 to which the charging sheet 7 has been bonded is appropriately collected by the fourth roller 17.

The filter 1 thus obtained has a laminated structure in which the nonwoven fabric substrate 2 is sandwiched between the upstream and downstream sheets 3 and 4 as shown in FIG. The nonwoven fabric substrate 2 is protected from friction during manufacture and use, and moderate strength is mainly given by the upstream and downstream sheets 3 and 4, so that folding can be easily performed. Also,
Since the upstream sheet 3 and the downstream sheet 4 have voids smaller than the granular adsorbent 5, the adsorbent 5 is reliably prevented from falling off during manufacturing or during use.

Further, since the dispersed particulate adsorbent 5 is entangled between the fibers 2a inside the nonwoven fabric substrate 2 and is maintained in a three-dimensional array state which is appropriately dispersed in the thickness direction, the adsorption performance is reduced. It is excellent and has excellent air permeability with small pressure loss. Moreover, since the adsorbent 5 is fused to the fibers 2a of the nonwoven fabric substrate 2 by the hot melt binder and the upstream and downstream sheets 3, 4 and the nonwoven fabric substrate 2 are fused, In addition to preventing the particulate adsorbent 5 from falling off, the upstream and downstream sheets 3 and 4 and the nonwoven fabric substrate 2 do not need to be separately bonded using a binder or the like, thus simplifying the manufacturing process. Be transformed into

Since the non-woven sheet 7 having a chargeability is bonded to the downstream surface of the downstream sheet 4, it is possible to remove even small dust that cannot be captured normally.
Since the charging sheet 7 is bonded after the heat treatment, the dust removing performance does not decrease due to the influence of the heat treatment.

[0041]

According to the present invention, the adsorbent is dispersed and held in the thickness direction of the nonwoven fabric base material, and the adsorbent is fused to the fibers by the hot melt binder, and the upstream and downstream sheets are used. Is fused to both surfaces of the non-woven fabric substrate and has a chargeability, so it has excellent adsorption performance and ventilation performance, does not drop off the particulate adsorbent, has excellent strength, and can remove small dust. A filter can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing an apparatus for manufacturing a filter according to an embodiment.

FIG. 2 is a cross-sectional view showing a simplified structure of the filter according to the embodiment.

FIG. 3 is a view showing a stainless steel mesh used for removing fine powder of activated carbon used in the filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Filter 2 ... Nonwoven fabric base material 2a ... Fiber 3 ... Upstream sheet 4 ... Downstream sheet 5 ... Granular adsorbent 6 ... Hot melt binder 7 ... Charged sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 53/04 B01D 53/04 A

Claims (6)

[Claims] 1. An upstream sheet and a downstream sheet having voids smaller than the adsorbent on the upstream and downstream surfaces of a nonwoven base material capable of dispersing a granular adsorbent in the thickness direction and holding the adsorbent therein. A filter in which a sheet is arranged, and a sheet of a nonwoven fabric having a charge property is joined to the downstream surface of the downstream sheet, wherein the adsorbent is mixed with a granular hot-melt binder in advance. The binder is sprayed on the nonwoven fabric substrate, and the binder fuses the adsorbent to the fibers of the nonwoven fabric substrate and fuses the upstream and downstream sheets with the nonwoven fabric substrate. filter. 2. The nonwoven fabric substrate has a basis weight of 20-10.
0 g / m ² , the thickness of the nonwoven fabric substrate is 0.5 to 10 mm, the average size of the adsorbent is 10 to 200 mesh, and the amount of the adsorbent sprayed on the nonwoven fabric substrate is 50 to 500 g / m2.
^2. The amount of the binder is 10 per 100% by weight of the adsorbent.
The filter according to claim 1, wherein the content of the filter is from 100 to 100% by weight. 3. A hot-melt particulate binder is fixed to one or both of the downstream surface of the upstream sheet and the upstream surface of the downstream sheet. The filter according to 1, 2. 4. One or both of an antibacterial agent and an antifungal agent is fixed to an upstream sheet or a downstream sheet in advance, or is mixed with the adsorbent and the binder and sprayed on the nonwoven fabric substrate. The filter according to claim 1, wherein the filtering is performed. 5. The filter according to claim 1, wherein the upstream sheet is coarser than the downstream sheet. 6. A nonwoven fabric substrate capable of dispersing the adsorbent in the thickness direction and holding the nonwoven fabric inside the downstream sheet having a void smaller than the granular adsorbent, From above, the adsorbent and the granular hot-melt binder are mixed and sprayed, the upstream sheet is placed on the nonwoven fabric substrate, and then the hot-melt binder is melted by heating. And the above-mentioned adsorbent is fused to the fibers of the non-woven fabric substrate, the above-mentioned upstream and downstream sheets are fused to the non-woven fabric substrate, and then the non-woven fabric having a charge property is formed on the downstream surface of the downstream sheet. A method for producing a filter, comprising joining sheets of a filter.